Ride height control valve



y 1958 v J. F. PRIBONIC 2,844,386

RIDE HEIGHT CONTROL VALVE Filed Jan. 18, 1957 3 Sheets-Sheet 1 [A f 4 43f0 4% J26 I33 w I37 [9. .l-HIIIIIIIIIH' A; 4! 4;; Law I I38 fa I35 HIGHR R 44 Pnissunz TANK TANK INVENTOR.

JOHN fi PRISON/l.

HIS ATTORNEY July 22, 1958 J. F. PRIBONIC 2,844,386

' V RIDE HEIGHT CONTROL VALVE I Filed Jan. 18, 1957 s Sheets-Sheet 2 1NVENTOR.

JOHN E P/I/B ONIC m Arron/var July 22, 1958 J. F. PRIBONIC 2,844,386

RIDE HEIGHT CONTROL VALVE Filed Jan. 18, 1957 3 Sheets-Sheet 3 I 8, I 0I L! z [/2 II" N I l //4' m0 70 v Q a INVENTdR. JOHN I. Pfl/BON/C Hi8 ATTURNE V United States Patent RIDE HEIGHT CONTROL VALVE John F.Pribonic, Dayton, Ohio, assignor to General Motors Corporation, Detroit,Mich, a corporation 0t Delaware Application January 18, 1957, Serial No.634,929

4 Claims. (Cl. 280-124) This invention relates to a fluid suspensionsystem for vehicles and to controls for regulating the clearance heightbetween the sprung mass and the unsprung mass of the vehicle.

In fluid suspension systems of the prior art it has been conventional toprovide controls adapted to maintain a predetermined clearance heightbetween the sprung mass and the unsprung mass of a vehicle so that theclearance height will remain the same irrespective of load conditions inthe vehicle. However, under the present trends of lowering clearanceheight between the sprung mass and the unsprung mass of a vehicle, thereare times when the clearance height is insuflicient to permit thevehicle to be driven onto a ramp that was built many years ago and wasconstructed to the dimensions of the old motorvehicles. Also, whenvehicles having a relatively low clearance height operates on a heavilyrutted road, the clearance height is sometimes insufficient to permitthe vehicle to clear the road in a satisfactory manner.

It is therefore an object of this invention to provide a suspensionsystem utilizing a fluid spring that is arranged to provide for a normallow level clearance height between the sprung mass and the unsprung massof the vehicle under all normal riding and traveling conditions, but toprovide for a rising of the clearance height between the sprung mass andthe unsprung mass under control of the operator of the vehicle in theevent the normal riding clearance height is insufficient to clear anyobstruction beneath the vehicle.

It is also an object of the invention to provide controls for supplyingfluid to an exhausting fluid from the fluid spring of the suspensionsystem whereby anormal relatively constant clearancexheight can bemaintained between the sprung mass and the unsprung mass of the vehicle,the controls providing for a supply of fluid to the fluid spring toincrease the clearance height between;

thesprung massand the unsprung mass at the will of the operator of thevehicle.

In accomplishing the foregoing objects it is another object of theinvention to provide a control device adapted to regulate the supply offluid to a fluid spring and exhaust of fluid froma fluid spring in amanner that a normal clearance height is maintained between the sprungmass and the. unsprung mass of the vehicle, the control being responsiveto the changes in clearance height between the sprung mass and theunsprung'mass whereby any corrections will be made by the control deviceto maintain the predetermined clearance height irrespective of .loadconditions in the vehicle. The control device is also provided with abypass valve arrangement whereby fluid can be suppliedto the fluidspring through the normal exhaust passage in the control device andthereby bypass the controlto provide for increasing the clearance heightbetween the sprung mass and the unsprung mass of the vehicle.Inaccomplishing this operation an. additional control is provided thatis under control of the operator of the vehicle for connecting thenormal exhaust line of the suspension system with the high pressurefluid source so that for a temporary period as desired by the operatorof the vehicle high pressure fluid can be supplied to thefiuid springthrough the normal control valve by way of the exhaust line connectedwith the control valve to raise the clearance height to an above normalcondition.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein apreferred form of the invention is clearly shown.

In the drawings:

Figure l is a diagrammatic representation of a fluid suspension systemincorporating features of this invention and controls for accomplishingthe result of the invention.

Figure 2 is a transverse cross sectional view of a valve mechanism foraccomplishing the results of the invention.

Figure 3 is a cross sectional view taken along line 33 of Figure 2.

Figure 4 is a cross sectional view taken along line 44 of Figure 2.

Figure 5 is a cross sectional view taken along line.

55 of Figure 4.

Figure 6 is a cross sectional view of a unidirectional bypass valveprovided for bypassing the exhaust valve of the control of Figure 2.

Figure 7 is a cross sectional view taken along line 7 '7 of Figure 2.

Figure 8 is a cross sectional diagrammatic representation of the controlvalve located within a fluid spring for accomplishing the feature of theinvention.

Figure 9 is a schematic representation of an electrical control for-theauxiliary operated control valve that-bypasses the main control valve ofthe fluid suspension system.

In this invention there is illustrated diagrammatically in Figure l afluid suspension system for a motor vehicle wherein the vehicle consistsof a front axle 10 and a rear axle 11. Fluid suspension units 12 and 13are located between the rear axle 11 and the chassis 14, the rear axle11 being an unsprung mass while the chassis 14 is the sprung mass of thevehicle. units 15 and 16 are located between the lower control arms 17and 18 and the chassis 14a.

The front end suspension system comprises the lower control arms 17and'18 pivotally carried on the chassis 14a by thepivot connections 28and 21. Upper control' arms 22 and 23 are pivotally supported on thechassis 14:: by the pivot connections 24 and 25. The control arms 17 and22 are pivotally connected with the steering knuckle 39 by the pivotconnections 26 and 27 while the control arms 18 and 23 connect with asimilar steering knuckle 28 by the pivot connections 29 and 30. Thewheel 31 is carried on the steering knuckle 39 and wheel 32 is carriedon the steering knuckle 28. The rear axle 11 supports the wheels 33 and34.

Each of" the fluid springs 12, 13, 15 and 16 consist of 'almetalcontainer 35 having a flexible diaphragm or bellows 36 secured in theopen end 37 of the container 35. -'Ihe"container 35 is secured directlyto the chassis 14 whereas the flexible bellows'or diaphragm 36 supportsthe axle 11 or the lower controls arms 17 and 18 of the frontsuspensionby way of a support member 38. The flexible diaphragm 36 or bellowsallows for movement of the rear 'axle 11 relative to the chassis 14 andalso allows movement of the lower control arms 17 and 18 relative to thechassis frame 14a, thus providing for a resilient suspension unitbetween the respective rear and front axle suspensions and the chassisof the vehicle. Each of the fluid suspension units 12, '13, 15 and 16'are-filled-with a fluid under pressure, preferably air,

Similarly, fluid suspensionv whereby to allow movement of the axlesrelative to the chassis and provide for resilient suspension of thechassis on the axles. Air suspension or air springs of this general typeare known in the art and further description of them is therefore notbelieved necessary.

Since air is the preferable medium of suspension, the spring units willhereinafter be referred to as air spring units, but it will berecognized that combination units such as air and oil can also be usedin place of the straight air spring as illustrated in the drawings.

Air under-pressure is obtained from a pump 40 that is driven in anysuitable manner, preferably by way of a belt from the engine of thevehicle. The pump 40 delivers air under pressure through the conduit 41into the high pressure supply tank 42. The maximum pressure. availablein the high pressure supply tank is regulated through suitablecontrolsin the pump 40 by way of the. control line 43. Such pressure regulatingcontrols for maintaining maximum pressure in the high pressure.

tank are well known and are therefore not further disclosed nordescribed.

High pressure air is delivered from the supply tank 42 through theconduit 44 and by way of the high pressure chamber 45 in the controlvalve 50 to the supply conduit 46 that is connected with the inlet valveof the levelizing control valves 51, 52, 53 and 54 of the respective airsprings 15, 16, 12 and 13.

Each of the levelizing control valves 51, 52, 53 and 54 are adapted toprovide air into the respective air springs or to exhaust air from therespective air springs through the exhaust line 47 whereby to maintain apredetermined clearance height between the unsprung mass or axles andthe sprung mass or chassis of the vehicle.

From the levelizing control valves 51, 52, 53 and 54, line 47 connectswith an exhaust chamber 55 in valve 50 and it in turn connects withanother exhaust chamber 56 that has the conduit 57 extending therefromwhereby the exhaust air emitted from the air springs 12, 13, 15 and 16by the respective levelizing control valves is delivered to the lowpressure air tank 58. The low pressure air tank 58 is connected with thesuction side of the air pump 40 by way of the conduit 59. The lowpressure air tank 58 is provided to receive the exhaust air from the airsprings so as to conserve air supply and to avoid continuous suction ofatmospheric air into the air suspension system by the pump 40. Thus theair suspension system is a closed system and only needs to draw in airfrom the atmosphere in the event air is lost from the suspension system.

Since all of the levelizing control valves 51, 52, 53 and 54 are ofidentical construction only one of them is illustrated in Figures 2-7inclusive and will be described herein.

Each of the levelizing control valves comprises a valve body 70, asshown in Figure 2, that is circular in transverse cross section and hasthe periphery 71 of a diameter just sufficient to fit within theinternal diameter of the bore or sleeve 72 that extends from thecontainer 35 of the air spring. The body 70 has a nut 73 thereon thathas internal threads engaging the external threads 74 on the externalperiphery of the sleeve 72 whereby the body 70 is retained in the sleeve72 and thereby positioned within the air spring 12. An ring'seal 75 isprovided between the valve body 70 and the internal periphery of thesleeve 72 to prevent loss of air from within the air spring 12.

The valve body 70 is provided with two passages 76 and 77 that extendparallel with the axis of the body 70, passage 76 providing a highpressure air inlet passage while passage 77 provides an exhaust passagefor escape of air from within the air spring. Each of the passages 76and 77 have passage portions 78 and 79 that are radial of the passages76 and. 77 and generally tangential to the axis of the body 70, as shownin Figure 4. These pass ge 78 n 7. a cl s by h rubber v v m m-- bers 80and 81 that are carried on the valve devices 82 and 83 respectively.

Each of the valve devices 82 and 83 comprises a generally U shapedmember that has ears extending upwardly therefrom to pivot the valvedevices 82 and 83 on the shaft 85 that projects outwardly from the body70, as more particularly shown in Figure 2. The valve device 82 has thecars 90 and 91 that provide support of the valve device 82 on the shaft85. Similarly, the valve device 83 has the ears 93 and 94 that providethe support of the valve device 83 on the shaft 85. A torsion spring 95is located around the shaft 85 and has its opposite ends 96 and 97engaging the respective valve devices 82 and 83 whereby to hold thevalve elements and 81 against the ends of the passage 78 and 79 to closethe inlet and exhaust passages against flow of air either into or out ofthe air spring 12.

An actuating member 100 is provided to operate; the valve devices 82 and83 to open them and thereby pro,- vide for inlet of air to the airspring or exhaust of. air from the air spring under control of theactuating device 100 to maintain a predetermined clearance heightbetween the sprung mass and the unsprung mass of the vehicle. As'shownin Figures 1 and 8 the actuating device 100. engages the upper surfaceof the diaphragm or bellows 36 and therefore responds to any change inclearance height between the sprung mass and the unsprung mass of thevehicle. As the load in the vehicle increases tending to move the sprungmass downwardly toward the unsprung mass, the acutating device 100 willopen the air inlet valve 82 and allow air to be supplied intothe airspring and compensate for the increase in load and bring the clearanceheight between the sprung mass and the unsprung mass back to thepredetermined normal position.

When the load decreases in the vehicle with the result that thediaphragm 36 or bellows tends to move upwardly of the air spring, theactuating device 100 will open the exhaust valve 83 and allow air toescape from the air spring and thereby allow the sprung mass to settleto the predetermined clearance height to which the device is regulated.

The actuating device 100 comprises an arm 101 carrying a nylon roller102 on the end thereof that engages the upper surface of the diaphragmor bellows 36. The opposite end of the arm 101 is integral with aU-shaped bracket 107 that has the opposite ends 103 and 104 carried onthe shaft and thereby provides for pivotal rotation of the actuatingdevice on the shaft 85. arm 101 and bracket 107 are retained on theshaft 85 by means of a C-washer 108 that'fits in a groove in the end ofthe shaft 85. Bushings 105 and 106 supportthe ends 103 and 104 of thebracket 107 on the shaft 85 to reduce thefriction of rotation of theactuator 100.

A second torsion spring 110 is provided around the shaft 85 and has oneend 111 thereof engaging a stop pin 112 on the valve body 70 and theopposite end 113 engaging the bracket 107 whereby the actuating device100 is normally urged in one direction of rotation by the torsion spring110 being clockise as viewed in Figure 7.

The ear 104 of the bracket 107' has radially extending ears 114 and 115.The ear 114 is adapted to engage the projecting portion 116 of the valve82 whereas the ear engages the projecting portion 117 of the valve 83 toactuate the respective valves upon rotation of the actuating device 100.When the actuating device 100 rotates in a counter-clockwise directionto rotate the bracket 107 in the same direction, as viewed in Figure 7,the ear 114 will open the valve 82 and allow airto be admitted into theair spring to offset an increase in load in the vehicle. On the otherhand, when the actuating device 100 rotates in a clockwise directionabout the shaft 85, as viewed in Fig.- ure 7, the ear- 115 will engagethe valve 83 and thereby open the exhaust port to allow air to escapefrom the air spring when; the load decreases in the vehicle and therebyTheallow the sprung mass to return to the predetermined normal positionrelative to the unsprung mass. The car 114 is adapted to engage the stoppin 112 when the valve device is either outside the air spring or whenthe diaphragm 36, movesdownwardly to an abnormal extent, therebylimiting the degree of movement of opening of the exhaust valve 83 atany time. I, Thevalve as hereinbefore described provides for normallevelizing or ride height control of the sprung mass relative to theunsprung mass of the vehicle so that irrespective of the load carried bythe vehicle the sprung mass will be maintained at a relatively constantclearance height relative to the unsprung mass.

There are conditions under which however it is desirable to elevate theunsprung mass to an above normal clearance height relative to theunsprung mass, for example, when placing a vehicle on a filling stationramp that has been designed for older type vehicles having relativelyhigh clearance between the ground and the chassis of the vehicle. Themodern automobile has considerably less clearance height between theroad and the sprung mass of the vehicle making it impossible undercertain conditions to place a-vehicle on lubrication racks of variousgarages thathave been designed to take care of the older type vehicleshaving a high road clearance. Under these circumstances itis desirableto provide for a temporary increase in clearance height between the axleof the vehicle and the frame so as to allow the vehicle to be placed onthe lubrication ramp. 7 The controls of this invention are thereforeprovided with auxiliary controls by which the normal predeterminedclearance height between the sprung mass and the unsprung mass of thevehicle can be increased.

lForithis purpose the valve body 70 is provided with a unidirectionalcheck valve 125 that is located in a chamher 126 adjacent the exhaustpassage 77. The chamber126 is connected with the exhaust passage 77 byway of the passage 79 that extends from the passage 77 into the chamber126. Thus the pressure that existsin the exhaust passage 77 can alsoexist in the chamber 126.

The check valve 125 consists of a stem 127 that supports a double lippedvalve member 128 that'is of the character that when the pressure on theleft hand side of the valve ,is higher than the pressure on the righthand side of the valve member 128 no flow of fluid is allowed throughthe valve member 128. However, when the pressure in the valve chamber126 is higher than the pressure on the left hand side of the valve 128,flow of fluid can pass in a left hand direction from the chamber 126into the interior of the air spring. This situation can occur only whenfluid under pressure is admitted into the exhaust line 47 of the airsuspension system illustrated in Figure 1. However, this situationcannot exist except under control of the valve 50 that is regulated orcorn trolled by the operator of the vehicle by means of the Bowden cable130.

The valve member 50 includes a valve spool 131 that has the lands 132and 133 that form the exhaust chambers 55 and 56 heretofore described. Adisk valve 135 is normally supported on the valve seat 136 by means of aspring 137 whereby the air inlet chamber 45 heretofore described is outof communication with the exhaust chambers 55 and 56. The exhaustchamber 55 communicates with the exhaust chamber 56 through a passage138 in the valve spool 131.

The valve 50 is illustrated in Figure 1 as in the normal position toallow normal operation of the levelizing control valves 51, 52, 53 and54 to maintain a predetermined clearance height between the sprung massand the unsprung mass of the vehicle. Under this condition of theposition of the valve 50, fluid under pressure is delivered from thehigh pressure tank 42 through the line 44 and 46 into the air springs12, 13, 15 and 16 under control of the levelizing control valves 51, 52,53 and 54. Exhaust of fluid from the air springs is delivered throughthe ex- 6 haust line 47 through the valve 50 andthence through thepassage 138 of the spool 131 to the chamber 56 and thereby through theconduit 57 to the low pressure tank as permitted by the levelizingcontrol valves in a manner hereinbefore described.

Under conditions wherein the operator of the vehicle desires to providefor an abnormal clearance height between .the axle and the chassis ofthe vehicle, that is give the vehicle an above normal road clearance toprovide for clearing of some road obstruction or permit placing the caron a ramp, the Bowden cable 130 is actuated manually by the operator ofthe vehicle to move the valve spool 131 of the valve 50 in a right handdirection whereby the end of the spool engages the valve disk 135 toclose the passage 138. Simultaneously the valve 135 is lifted from itsseat 136 whereby the high pressure chamber 45 communicates with theexhaust chamber 55. Since the passage 138 is closed, no high pressurefluid can escape to the low pressure tank through the line 57. Hence,the direct connection of the high pressure chamber 45 with the exhaustchamber 55 supplies the exhaust line 47 with high pressure fluid and itin turn supplies the check valve with high pressure fluid so that atthis time fluid under pressure can pass in a left hand direction aroundthe outer periphery of the double lipped valve 128 into the air springin exactly the same manner as though the inlet valve 82 of the controlvalve 70 was open. So long as the operator of the vehicle maintains thespool valve 131 in a right hand position as heretofore described, airunder pressure will be supplied to the air springs 12, 13, 15 and 16 toelevate the chassis of the vehicle relative to the axles and therebygive an abnormal clearance height to the vehicle.

The degree of increase of clearance height allowed the vehicle by theoperation heretofore described is regulated by suitable limit stopsbetween the axle and the frame of the vehicle, not shown.

Whenever the operatorof the vehicle desires to return the vehicle to itspredetermined clearance height and restore the normal operation of thelevelizing and height control valves 51,52, 53 and 54, the Bowden cableis moved in a left hand direction to move the valve spool 131correspondingly to return it to its position illustrated in Figure 1.When this occurs, since the vehicle is already riding at an abnormallyhigh clearance height relative to the axle, the actuating member 100 ofthe levelizing and height control valves 51, 52, 53 and 54 will be inposition to effect opening of the exhaust valve 83 of the control valvesof the respective air springs. This will allow air to exhaust from therespective air springs until such time as the exhaust valves close whichindicate that the vehicle is returned to its normal clearance heightrelative to the axle.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, :it is to be understood that other formsmight be adopted as may come Within the scope of the claims whichfollow.

What is claimed is as follows.

1. In a fluid suspension system for controlling the clearance heightbetween the unsprung mass and the sprung mass of a vehicle, a fluidspring positioned between an unsprung mass and a sprung mass of avehicle, a fluid pressure source, a first control means responsive tochanges in clearance height between the unsprung mass and the sprungmass controlling supply of fluid from said source to said spring andexhaust of fluid from said spring to maintainthereby a normalpredetermined clearance height between the sprung mass and the unsprungmass, and a second control means under control of the operator of thevehicle effective to supply fluid from said source to said exhaust ofsaid first control for supply of fluid pressure from said source to saidspring through said exhaust and efiect an above normal clearexhaustchamber 55 of the 7 "ance height between the sprung mass and theunsprung mass.

2. In a fluid suspension system for controlling the clearance heightbetween the unsprung mass and the sprung mass of a vehicle, a fluidspring positioned between an unsprung mass and a sprung mass of avehicle, a fluid pressure source, a first control means responsive tochanges in clearance height between the unsprung mass and the sprungmass controlling supply of fluid from said source to said spring andexhaust of fluid from said spring to maintain thereby a normalpredetermined clearance height between the sprung mass and the unsprungmass, and a second control means having a high pressure inlet chamberconnected with said source and a low pressure exhaust chamber, conduitmeans connecting said chambers with said first control means for supplyof fluid under pressure to said first control means and through whichexhaust fluid is received from said first control means, said secondcontrol means having valve means therein actuable under control of theoperator of the vehicle to connect said inlet chamber with said exhaustchamber for supply of fluid under pressure from said source to saidfirst control means through the exhaust conduit connected therewith.

3. Ina fluid suspension system for controlling the clearance heightbetween the unsprung mass and the unsprung mass of a vehicle, a fluidspring positioned between an unsprung mass and a sprung mass of avehicle, a fluid pressure source, a first control means havingindependently actuable valve devices one of which functions as an inletvalve for connecting said source with said spring and the other of whichfunctions as an "exhaust valve to exhaust fluid from said spring andincluding actuating means engageable with said valve devices to open andclose the same and responsive to changes in clearance height between'thesprung mass and unsprung mass for inlet of fluid to the air spring orexhaust of fluid therefrom to maintain a normal predetermined clearanceheight between the sprung mass and the unsprung mass, said first controlmeans including 'an additional valve means connecting said spring withexhaust but openable opposite to said exhaust valve to providefor'supply of fluid from exhaust to said spring, and a second controlmeans under control of the operator said spring to effect an abovenormal clearance height between the sprung mass and the unsprung mass.

4.111 a fluid suspension system for controlling the clearanceheight-between the unsprung mass and the sprung mass of a vehicle, afluid spring positioned between-an unsprung mass and a sprung mass of avehicle, a fluid pressure source, a first control means havingindependently actuable valve devices one of which functions as an inletvalve for connecting said source with said spring and the other of whichfunctions as an exhaust valve to exhaust fluid from said spring andinclud- 'ing actuating means engageable with said valve devices to openand close the same and responsive to changes in clearance height betweenthe sprung mass and unsprung mass for inlet of fluid to the air springor exhaust of fluid therefrom to maintain a normal predeterminedclearance height between the sprung mass and the unsprung mass, saidfirst control means including an additional valve means connecting saidspring with exhaust but openable opposite to said exhaust valve toprovide for supply of fluid from exhaust to, said spring, and a secondcontrol means "having a high pressure inlet chamber connected with saidsource and a low pressure exhaust chamber, conduit means connecting saidinlet chamber of said second control with said inlet valve of said firstcontrol, conduit means connecting said low pressure exhaust chamber ofsaid second control with said exhaust valve of said first control, saidsecond control means having valve means therein actuable under controlof the operator of the vehicle to connect said inlet chamber with saidexhaust chamber thereof for supply of fluid under pressure from saidsource to said first control through the exhaust conduit connectedtherewith and thus through said additional valve means to said spring toeffect an above normal clearance height between the sprung mass and theunsprung mass.

References Cited in the file of this patent UNITED STATES PATENTS

